code: def group_definitions(self):
      groups = defaultdict(list)
      for rev, rev_content in self.data.items():
          definitions = rev_content.get("definitions", {}).get(
              "data", {}
          )
          for plot_id, definition in group_definitions_by_id(
              definitions
          ).items():
              groups[plot_id].append((rev, *definition))
      return dict(groups)
  
file_path: dvc/dvc/render/match.py
imports: import os
  from collections import defaultdict
  from typing import TYPE_CHECKING, DefaultDict, Dict, List, NamedTuple, Optional
  import dpath
  import dpath.options
  from funcy import get_in, last
  from dvc.log import logger
  from dvc.repo.plots import _normpath, infer_data_sources
  from dvc.utils.plots import group_definitions_by_id
  from .convert import _get_converter
label_desc: Use image node_id 2 for calling the PlotsData obj's underlying member method code with example usage: obj.group_definitions() and returns: dict